I completely agree with OP, and I must say I've been exploring for about 30 hours now ( also doing main quest which is now completed and doing ALOT of side missions) and I'm almost done with this game. I mean what THE HELL!?? I'm level 28 now so almost at the level cap, this still bothers me but it was the same in fallout 3 (that you would reach you level cap WAY before you were done with the game). However, I've just about explored everything, I've discovered a hundred locations out of the 125 in the game (and been through all of them) I have found 8 special weapons already. And I have completed a ton of quest for various factions and talked to alot of people. But it only took me 30 hours. I'm guessing another 10 hours and I'll have just about anything explored.
The reason I'm so surprised about this all is because I have played fallout 3 for about 300 hours (I've also lost my very first character but I'm not sure how much I played with him), on multiple characters naturally but I could spend atleast a hundred 100 (if not 150) in one single character. But in new vegas I'm just about done after 40 - 45 and I'm not really looking forward to starting over again. People say that fallout 3 was empty but I couldn't disagree more. Sure fallout new vegas is FILLED with locations, but half of them are [censored] ones (abandoned shack anyone?) and you can run through them in a few minutes if not seconds. What I miss is DC, I've spent countless hours exploring that city but in new vegas there's nothing like that. And everywhere you look there's people! I like the concept of all the factions but they have focused to much on it, I don't want to find those bloody ncr at every twist and turn. I want these gritty ruins/underground tunnels to explore every once in a while, however in new vegas there's nothing like that to be found.
There's seriously a location which is searchlight airport (or something like that) and when I found it I was really excited for something big to explore. Guess what I can't enter a SINGLE building, it really feels to me like obsidian just put all their effort into the factions and then filled the rest of the world up with these [censored] locations. And then they put all these big mountains in, which could have been filled with tons of interesting stuff instead there's the rare cave that takes 10 seconds to search through and a MAZE OF FRIGGING INVISIBLE BARRIERS [censored] EVERYWHERE!!!! The world builders have done an unbelievable slack job if you ask me. I mean fallout 3 had some [censored] locations aswell but it was SOME and it also had DC to make up for it.
The next thing I'm particularly dissapointed about is jacobstown. I love the new super mutants over the "old" ones (referring to fallout 3) in every single way. I talked to everyone in jacobstown and did every quest. How many people did I talk to? 3.... How many quests did I do? 2.... How long did it take me to do it? an hour..... I'm so dissapointed that this wasn't fleshed out at all, they could've done so much more with this all this potential wasted. I would've liked to see much more quests and mutants to talk to. And this is not only the case in jacobstown it's the case in much more locations.
The very last thing I wanted to address is the sunset sarsaparilla factory as an example. In fallout 3 the nuka cola factory was filled with awesome and unique stuff! Nukalurks and a bunch of backgroundstory and history. In new vegas the sunset sarsaparilla factory was bland, had barely any backgroundstory and had a very hard locked door with literally nothing behind it except for some 10mm rounds. I take the sunset sarsaparilla factory as an example here because this is the case throughout the whole of fallout new vegas, in fallout 3 a big reason for me to go exploring was to find this unique stuff like nukalurks. In new vegas there doesn't seem to be any at least not in the 100 out of 125 locations I've discovered. Another example is a crashed vertibird somewhere in the wasteland with a prototype tesla cannons next to it (spoiler? well it's too late now) There was absolutely NO information about this whatsoever, just the cannon, the vertibird and some skeletons. I was spyched at finding the cannon but rather dissapointed afterwards. I am quite dissapointed in fallout new vegas, it seems bland, unfinished and empty (not story wise though).